Air brake mechanism



'April 20, 1937. A. l.. GooDKNlGHT AIR BRAKE MECHANI SM Filed Sept. 8, 1954 Patented Apr. 20, 1937 UNITED STATEE iATENT GFIQE 13 Claims.

This invention relates to air brake mechanism of the general type described in my prior Patents #1,736,910, dated November 26, 1929 and #1,835,999, dated December 8, 1931.

Broadly the invention seeks to provide air brake mechanism wherein all of the component elements function in such a manner as to afford suflicient and positive braking action at all times, and in which suicient pressure is maintained for any emergency notwithstanding excess air dissipation by the engineer or operator thereby providing a safe, dependable brake mechanism capable of meeting every emergency.

A certain standard of efliciency is required in the braking facilities of modern steam railways,

as well as electric and motor transportation, and

it is the primary purpose of this invention to meet such requirements and provide a simple and economical, yet durable construction which will enable expert operation by persons of average experience and training and which will eliminate the possibility of expanding and dissipating air pressure to the danger point, and which will maintain at all times a sufficient pressure to stop a train or other vehicle in a normal manner without skidding the same, and which will further prevent application of the service or emergency mechanism when not intended.

With the above and other objects in view the 30 invention consists of certain novel details of construction and combinations of parts hereinafter fully described and claimed, it being understood that various modifications may be resorted i to within the scope of the appended claims without departing from the spirit or sacriiicing any of the advantages of the invention.

In the accompanying drawing forming part of this specication The figure is a diagrammatic sectional View 40 of a brake controlling valve device constructed in accord-ance with the invention and showing the parts in normal release position.

Briey, this invention presents three novel features and their construction and advantages will .45 be described, explained, and stressed in the following speciiication, as:

First, when the brakes are operated, by, for example, 100 pounds pressure more or less, a brake cylinder maintaining device will compen- 50 sate for brake cylinder leakage and maintain .55 if the auxiliary reservoir becomes overcharged and the main slide valve of the triple valve portion begins to creep over and apply the brakes, an auxiliary reservoir deplete device will vent the excess auxiliary reservoir pressure to the atmosphere and positively prevent accidental application of the brakes.

Third, when the brakes are emergency applied the brake cylinder and auxiliary reservoiry equalizes with pressure of from 60 to 65 pounds which is 10 or 15 pounds excess pressure above the usual normal 50 pounds. Immediately following this operation a br-ake cylinder exhaust control device reduces the excess brake cylinder pressure in a chamber, in the brake cylinder, and in the auxiliary reservoir, such pressure release being made into the brake pipe whereby to facilitate a prompt brake release. y

Referring now to .the drawing, the invention is shown to comprise substantially five main devices which will be hereinafter referred to as the triple -valve device V, auxiliary reservoir deplete device W, brake cylinder exhaust control device X, emergency valve device Y, and brake cylinder maintaining device Z.

Triple valve device The triple valve device V comprises a housing I containing the main slide valve assembly which includes a piston d in the piston chamber 5, a piston stem 6, an auxiliary slide valve l, and a main slide valve 8. 'Ihe main slide valve is provided with the cavities 1l, i8, and 88', and also is provided with charging ports I3 and Gil', also with quick service ports 2 and l', and also With a service port 85. The auxiliary slide valve 1 is provided with a cavity 9.

The piston stem 6 is provided with a collar I2 which moves the main slide valve 8 when a reduction in brake pipe pressure is made. The piston stem is pressed by a helical spring 20 disposed on a pin i9. Movement oi the piston stem against the tension of the spring, when a release is made, is limited by Contact of a guide Il with -a stationary projection Z9. The pin terminates in an abutment 25.. which maintains the main slide valve 8 in position for full ,release by reason of the spring 2l! shoving the abutment back after auxiliary reservoir pressure has equalized with brake pipe pressure.

A feed groove 38 in the housing l forms a bypass around the piston l from the piston chamber 5 into the main slide valve chamber I. The piston is provided with an axial housing for a plunger 4', which is spring pressed outwardly by a spring 5. Exteriorly of the valve a stop lug 35 is formed integral with the piston for depressing the stop pin 29 under certain conditions.

The stop pin 29 engages the plunger with its tip 29. VYA helic-al spring 52 surrounds the stop 5 pin and in release position of the parts holds a collar 15 on the pin in engagement with a stop disc 36 having perforations 36 therein to establish communication between the piston chamber 5 and pin chamber 28.

Auxiliary reservoir deplete device The auxiliary reservoir deplete device W comprises -a piston |21 working in the piston chamber |28 and having a stem |21 upon which a 5 slide valve |36 is exibly mounted by means of a helical spring |3| The slide valve is mounted between spaced collars on the piston stem. At any time when brake pipe pressure in the chamber |28 exceeds auxiliary reservoir pressure in the chamber |28 plus pressure of a spring |32, the piston moves the slide valve to uncover a passage |38 which leads to the atmosphere for venting the auxiliary reservoir to the atmosphere. One of the collars is perforated so that auxiliary reservoir pressure from aApass-age |35 may enter the chamber |28 on both" sides of the valve.

Brake cylinder exhaust control device 0 The brake cylinder control exhaust device X comprises a piston |29 working in a chamber |46. The stem |48 of the piston is provided with a slide valve |41 having a cavity |49 therein. The piston stem is also provided with a passage |50 which extends through the slide Valve. In iull release position of the parts the passage |56 is out of registration with a passage |50 which leads to the brake cylinder, as will presently be described, but the passage |56 registers with the passage |50 when the brake pipe pressure has dropped below approximately 50 pounds to connect the brake pipe direct to the brake cylinder. The slide valve |41 also controls a passage |52 which curves around the slide valve housing and communicates with a passage |1| that is controlled by a check valve |10 and that opens into the brake pipe |44. The cavity |49 connects passages |53 and |53' which connect the brake cylinder to the atmosphere through the triple valve assembly V in full release position.

The piston |25 is held at one limit of its movement by brake pipe pressure in a chamber |59 which opens into the slide valve housing as shown. This chamber |69, it will here be stated, contains brake pipe pressure when the brakes are released but contains brake cylinder pressure when the brakes are applied.

A pin |62 is slidably mounted in a chamber 56 and is held pressed against the piston |29 by means of a helical spring |63. The spring is under a tension of about 50 pounds. Thus it will be compressed by greater than about 50 pounds pressure in the chamber |69. When the pressure in the chamber |69 is less than 50 pounds the spring |63 will move the piston |29 to carry the slide valve |41 to application position in which position the passage |50 will register with the passage and the valve will seal passage |52 as well as seal the passages |53 and |53.

Emergency valve device 75 thereon between which is mounted a slide valve 58 which seals a passage H2 in the slide valve housing when the parts are in full release position, as shown. The slide valve is provided with an equalizing port 55. A pin |31 is mounted in a chamber 66 which is in communication with the piston chamber 55 through openings 15 in the pin guide 1|. A spring 53 of about l0 pounds tension, surrounds the pin and urges the pin against a projection 12 on the piston.

A quick action chamber 52 in the bracket 8| is in communication with the valve housing, and the fluid pressure in the chamber is exerted against the piston 55 in opposition to the pressure of the spring 55. The chamber 52 is in communication with the auxiliary reservoir through passage 63 past check valve 64, and chamber The chambers 66 and 55 are in communication with the brake pipe through passages 15 and 5i). Consequently when a reduction of pressure, for instance of more than 10 pounds is made in the brake pipe and in the chamber 55, the pressure in the quick action chamber 62 will move the piston 55 until the port 66' in the slide valve registers with the passage H2 whereupon the pressure in the chamber 62 will reduce through the passage H2 until it reaches an excess pressure of about 10 pounds more than the pressure in the brake pipe, due to the spring exerting a pressure of about l0 pounds against the piston 56.

The passages ||2-| i3 open into the chamber 85 of a vent piston H4 which is provided with a port B that communicates with passages 54-53 leading to the brake cylinder. Pressure in the quick service chamber 62, reducing through the passage H2 when the port 56 in the valve 58 registers, will pass through the chamber 35, port B, passages 54-55 to the brake cylinder.

The piston stem carries a vent valve i i9 which controls a passage i8 leading through passages v 54 and 53 to the brake cylinder. The vent valve works in a chamber 5| which is controlled by a valve |23 that is slidably mounted on the stem |22 of the Vent valve. The spring |25 is interposed between the stem 22 of the vent valve and the check valve |23 and tends to constantly hold the check valve |23 and the vent valve l i5 closed. rI'he check valve controls brake pipe pressure from the passage 58 into the chamber 5|.

During emergency application, when pressure from the quick action chamber 52 moves the piston 56 to its limit of movement, the slide valve 58 will be moved to unseal the passage E52' and air in large volume will travel from the quick action chamber through the passages ||2-| I3 and move the vent piston H4 against the tension of its controlling spring i1. This movement of the piston opens the vent valve l i9 whereupon brake pipe pressure from the passage 48 will open the check valve |23 and permit brake pipe pressure to ilow in large volume into the chamber 5i past the valve H5 into the passages i5', 54 and 53 to the brake cylinder.

A quick service chamber 54 in the bracket 8| is in communication with the piston chamber 85 through passages ||6-95. The quick service chamber also communicates with a passage 9 which is controlled by the valve assembly 1-5 of the triple valve device V.

In full release position the quick service chamber 84 is in communication with the atmosphere through -l |6-85-B-54-53 and brake cylinder. During quick service application the chamber 84 is subjected to a definite volume of brake pipe air through passage NV-49, open the auxiliary reservoir 65.

check valve |23, passage I5', port 2', cavity 9' of main slide valve assembly 1`8, and passage 9a.

Brake cylinder maintaining device The brake cylinder maintaining device Z' comprises a check valve 39, the stem of Which ab-uts a pin 42 which is slidably mounted in a chamber 4|. A spring 43 surrounds the pin and exerts a pressure of about 50 pounds on the check valve 39. A passage 52 leads from the brakecylinder to va passage 51 which communicates with the chamber 4I. The check valve 39 closes a passage I6 Which is controlled by the position of the cavity I3 of the triple valve device V, the cavity I3, under service or emergency application, connecting the passage I6 With a passage I5 which leads into the passage I5 then to the brake pipe through the check valve |23 and passage 48.

During service application brake pipe pressure in the chamber I6, say, 60 pounds, will overcome the 50 pound tension of the spring 43 and will permit l0 pounds brake pipe pressure entering the brake cylinder through the passages 51-52. The brake cylinder pressure in the chamber 4I, 10 pounds, plus the pressure of the spring 43, 50 pounds, Will close the check valve 39. Should, however, there be leakage with consequent reduction from the l0 pounds pressure in the brake cylinder the check valve 39 Will again be opened 0 as above described to compensate for this loss of pressure.

When a retainer is to be used the plug 81 is transferred to the port |43 to pass the exhaust through the port 86 to the retainer. When this is done the plug 80 is transferred to the vent opening |51, and in this position dirt collecting in the chamber |50 will be vented through the opening 88.

Charging On the front end of the train where production is immediately felt the piston 4 moves at full transverse into retarded release and restricted recharge position to close the feed groove 38.

i' Brake pipe pressure noW flows through passage 43 past check valve |23 to passage I5 to port I3', to main slide valve chamber I0. When the auxiliary reservoir pressure becomes substantially equal to the brake pipe pressure, the spring shoves the main slide valve and piston assembly back to full release position as shown in the figure and noW brake pipe pressure can also oW from passage 48-15 to chamber 5, through now open feed groove 38 into the main slide valve chamber I0'.

Fluid from the auxiliary reservoir and its chamber I0 flows through passage D-63 past check 64 into quick action chamber G2'-62. Piston 56 remains in the position shown because of the presence of brake pipe pressure owing from passages 48 and 49 to passage 13 into chamber 35 of the emergency piston assembly and pressure of spring 68 in chamber 66. Fluid under pressure also ov/s from passage D through pipe 65 to When pressure in chamber I0' approaches that in chamber 5 spring 20 shifts the main piston assembly 4--6-1-8 into the position shown. Feed groove 38 is open. Communication with passage I5' and chamber I0 is maintained by slide valve port 64.

The brake cylinder is connected to the atmosphere as follows: brake cylinder pipe 53, passage 54-43, cavity 11 in main slide valve 3, passage 12'-I 53, cavity |49 of the direct air piston assembly I41-I48-I29, passage |53', chamber |56 and port |51. Brake pipe pressure also flows from passage 481`5 to passage |42 into chamber |28 of theA deplete valve assembly |21-I30 moving it into the position shown so that passage |35 is connected to the atmosphere via passage |39. Brake pipe pressure also flows from passage I5 via passage 83, cavity 83', passage 83 to reservoir chamber 80. Brake pipe air also flows from pipe |44 to passage I1| past check valve |10 into chamber |39. When the pressure in chamber |59 reaches a value suflicient to compress spring |63 (about 50 pounds) the piston |29 moves into the position shown to connect the brake cylinder passage |53 to the atmosphere, as already described.

Service operation Reduce brake pressure from 70 pounds to 60 pounds.

Main piston assembly moves first to close feed groove and port 83, connect quick service ports 2 and 1' in main slide valve 8 via cavity 9 in auxiliary slide valve 1 and open service port 85' in main slide valve. Thereafter' main assembly moves into quick service position with ports 85 and 43' partly open to apply the brake With reservoir and quick service pressures (e. g. piston lug 35 abuts stop 29 Without compressing same). The brake pressure is vented to the quick service chamber 84 via |5-2'-91-9a and also into the quick action piston chamber 85 through ports 90 and II6. Some of the air may leak through port B to brake cylinder passage 53. This Will propagate the quick service brake application by venting the brake pipe in a chamber of xed volume. The main valve assembly then moves to service position wherein spring pressed stop pin 29 is partly overcome. The brake pipe is noW connected to the brake cylinder via I5'-|5, cavity I3-|6, past check valve 39, passage 51-52 and 52 to brake cylinder pipe 53, In this position the auxiliary reservoir is fully connected to the brake cylinder 53 via main slide valve service port 85 and passage 43. The auxiliary reservoir is also connected to chamber |28 of the deplete valve |30 via port I4 in the main slide valve seat and connected passage by movement of the main slide valve from release position. Chamber |28 has been isolated from the atmosphere in view of movement of piston |21 and its associated valve |30 under influence of reduced brake pipe pressure and auxiliary reservoir pressure admitted to said chamber. This conditions the deplete valve for a function hereinafter described. Upon equalization of the auxiliary reservoir with the brake pipe the piston 4 will move the auxiliary slide valve 1 to lap position to close the service port 85'. The cavity I3 still maintains the connection of the brake pipe to check valve chamber I5. If brake cylinder pressure is diminished by leakage to a value less than lO pounds the check valve 39 will act to charge the brake cylinder from the brake pipe back to 10 pounds in a manner new described. Spring 43 seats valve 39 with a force of approximately 50 pounds. Train pipe pressure in chamber I6 is 60 pounds, e. g. said train pipe pressure having been reduced from 70 pounds to 60 pounds. Thus if the brake cylinder pressure present in chamber 4| plus the tension of spring 43 is less than 60 pounds the check valve will be unseated by the 60 pound brake pipe pressure to bring the brake cylinder up to a value suiiicient to close said valve, in this case back to 10 pounds.

It may thus be seen that there will be maintained in the brake cylinder at all times during service a pressure equal to the difference between the value of spring 43 and the reduced brake pipe pressure provided the brake pipe pressure is not reduced to a value less than spring d3, e. g. 50 pounds. The emergency piston assembly will move, during service, just suiciently to bleed the quick action chamber 62-52 into the quick service chamber and brake cylinder via port $5 and passages II2, IIS and port B at a rate commensurate with a service rate of brake pipe reduction. This prevents a suiiicient pressure diierential from building upon piston 5S to move same into emergency position.

If the auxiliary reservoir and brake cylinder pressure has been depleted to a point where it is no longer possible to admit fluid under pressure to the brake cylinder by a reduction in brake pipe pressure the brak-e cylinder pressure may be maintained directly by the engineer in the following manner. After the brake pipe pressure has been reduced to 50 pounds the auxiliary reservoir will have equalized with the brake cylinder. No further air may then be supplied from the auxiliary reservoir to the brake cylinder. However, when brake pipe pressure is reduced by the engineer to a. value less than 50 pounds piston E29, under influence of about 59 pounds spring IES, will move to the right. This will connect the brake pipe directly to the brake cylinder through the following passages, brake pipe Ml- AMV-lll past check valve I'I, chamber its, port 53 and |50 connected to brake cylinder passages 52 and 52. It may thus be seen that the engineer may maintain the brakes applied by supplying air directly thereto in all cases Where the brake pipe pressure is less than value of spring E63.

The maintained pressure may be any value less than 50 pounds e. g. l0, 20, 30, etc. To release the brake it is necessary to increase brake pipe pressure since the main piston assembly performs the release function.

Release after service To release the brakes the engineer places the engineers valve in the usual position to supply air to the brake pipe. When the brake pipe pressure reaches a value of 50 pounds the direct air valve assembly lill-|58 moves to the left or release position disconnecting the brake cylinder from the brake pipe. Rising brake pipe pressure will also be effective on the main piston assembly to move same to release position. Also when brake pipe pressure is slightly greater than the reduced auxiliary reservoir pressure eiiective cn piston I2I it will move to the right tc vent auxiliary reservoir. This venting will continue until the main assembly moves to release after which main slide Valve blanks port 4 to prevent waste of air. Movement of the main valve assembly connects the brake cylinder to atmosphere via passage 43', exhaust cavity il, passage 'I2-I53, cavity M9, passage les-3l to the usual retainer valve connection 88.

Movement of the main slide assembly to release position also connects the reservoir chamber 8S to the auxiliary reservoir via passage 83 opening into the main slide valve seat. This will aid a rapid recharge of the auxiliary reservoir by equalizing therewith, Thereafter the auxiliary reservoir, reserve chamber and quick action chamber are charged from the brake pipe in the already described manner.

It is to be noted that final exhaust of brake cylinder pressure is under control ofthe direct air valve. The purpose of this is to prevent release of the brakes when the direct air valve is in application position because of depletion of auxiliary reservoir pressure or unintentional movement of the main valve to release position when controlling the brakes directly.

II the auxiliary reservoir should become overcharged, the main valve 8 will creep slowly under influence of such excess pressure and uncover ports Ic-Ili and the deplete valve |30 has the vent port It open thereby permitting the excess pressure to vent slowly to the atmosphere until normal pressure of 70 pounds is retained in the reservoir.

Emergency When an emergency reduction in brake pipe pressure is initiated the main valve assembly moves its full traverse to the left. In this position main slide Valve 8 connects the brake pipe with valve chamber I6 via brake pipe passage 48 past check valve |23, passage I5', I5, cavity I3 and passage i6. The result is to vent brake pipe air to the brake cylinder until the combined force of spring 13 and brake cylinder pressure in chamber lll is equal to the force of brake pipe air pressure present in chamber IB acting on check valve 39. Also the main slide valve 8 has opened a restricted communication between the auxiliary reservoir and the brake cylinder e. g. passage 43 is not fully opened by the tail portion of said slide valve. Thus during this first period there is a relatively slow flow of air from the brake pipe and auxiliary reservoir to the brake cylinder.

W hen the brake pipe drops to a value approximately pounds below the initial pressure the emergency piston assembly moves to the left (spring 68 exerting a force of approximately 10 pounds on the piston assembly) to establish an unrestricted communication between the quick action chamber 62-62' via passages H2' to the top of quick action piston H4. Piston IM then acts to open valve I I9 to provide an unrestricted ow of air to the brake cylinder from the brake pipe. This flow Will continue until the brake pipe pressure equalizes with that in the brake cylinder at which time check valve |23 acts to prevent any reverse flow. This second period acts to accelerate the rate of build up of brake cylinder pressure commensurate with the volume of air vented thereunto from the brake pipe. Thereafter (3rd period) brake cylinder pressure continues to build up at a rate less than the initial rate by an amount depending upon the quantity of air that was supplied by the now inactive check valve 39 and the retarded auxiliary reservoir pressure held back by the restricted port 133.

It may be seen that in emergency there are three rates of charge for the brake cylinder. The first period permits the gathering of slack since nal venting of the brake pipe into the brake cylinder is delayed until the second above described peried. In the third period equalization between the auxiliary reservoir and brake cylinder takes place at a rate determined by the opening of port llt. This equalization pressure is approximately sixty five pounds. The direct air Valve assembly acts, when the brake pipe is Vented as in emergency, to bleed this pressure down to fifty pounds as follows. When brake pipe pressure drops to a value less than fty pounds piston IES moves to the right under iniiuence of spring ISS to isolate the brake pipe from chamber |69. The brake cylinder is then connected to chamber |69 via passage 52-52, |59 and port |59. Since the brake cylinder pressure is approximately 65 pounds the flow of air into chamber |59 will build up until it is slightly in excess of fty pounds, the value of spring |63. This piston |29 Will then move to the left causing slide valve I 4l to blank the brake cylinder passage |59 and connect chamber |69 to the novv vented brake l0 pipe chamber Il! through port |52. When chamber |59 has vented piston |29 Will again move to the right to continue its cycle operation until brake cylinder pressure has dropped 'to a value such that spring |63 can no longer be over- 15 come.

Since the auxiliary reservoir is connected to the brake cylinder through ports 35 and 43 While the main piston assembly is in application position it too Will be reduced to fty pounds 20 pressure. The purpose of this reduction in equalization pressure is to enable a ready quick release of the brakes to be obtained. That is to say With this device it is only necessary to raise the brake pipe pressure to slightly above fifty pounds to 25 effect release instead of sixty ve pounds. Like- Wise should the main assembly fail to move into release position immediately the automatic deplete valve will act to vent the auxiliary reservoir as described under Release after service. To

30 release the brakes after an emergency brake application the usual brake valve Would'bey operated to charge the brake pipe. rIhe mechanism will then operate as described in Release after service.

35 The quick service feature operates the same in` high abnormal as it does in normal .pressure and in the quick service operation the compensation valve 39 is not yet cut in. Reference is had to the accompanying figure. To bring about a, service 40 and compensation app-lication of the brakes when operating, for example, With 100 pounds brake pipe, auxiliary reservoir and 120 pounds of mainA reservoir pressures, a reduction of pounds of brake pipe pressure .to the atmosphere with the 45 engine brake valve is made more rapidly than that of the auxiliary reservoir flows through the port 85 and passage 43 into the brake cylinder53.

The diierenoe in pressure on both sides of the piston 4 soon becomes suircient to movethe pis- 50 ton 4 and its valves 'I and Stewards the spring pressed stem 29.

The piston 4 compresses the graduating spring 32 and causes the valve 8 to move enough to register the port 85 fully open with the port or passage :55 43 and thus permit a like amount of pressure,

which is 10 pounds of auxiliary reservoir pressure, toy reduce into the brake cylinder. The auxiliary reservoir being much larger than the brake cylinder, will cause the 10 pounds reduction of 60 pressure from the former into the latter to develop to approximately 25 pounds pressure (more or less), in combination With the compensation pressure flowing into the brake cylinder from the brake pipe passage 49 through the compensation ,65 ports I5', I5, cavity I3 and port I6, lifts valve 39,

compresses spring 43, passes through ports 51 andl The by-pass cavity I3 connects port I5 connected to port I5' (see figure). The abnormal brake pipe pressure in passage 49 Will then force the valve |23 to rise from its seat and flow into chamber 5| through ports I 5', I5, cavity I3, thence through port I6 to the valve 39. It Will then lift the valve 39, compress spring 43. and pass into chamber 4I, then through passages 5'I and 52 and thence into the brake cylinder 53, which causes a localv direct reduction of brake pipe pressure through the latter ports and passages into.l the brake cylinder to accelerate the propagation of the application and thus continues to apply the brakes. with a greater brake cylinder pressure until the brake pipe, auxiliary` reservoir and brake cylinder pressures, plus the spring 53 resistance, equalize, Whichis approximately 861/2 pounds of air pressure in the brake pipe and auxiliary reservoir and 361/2 pounds of air pressure, plus the 50 pounds resistance of spring 43 in the brake cylinder chamber 4I` and its connected brake cylinder 53. The valve 39 Will then close. If there should be any brake cylinder leakage, it will then open and compensate for the same and hold the brakes set With air pressure direct from the brake pipe (see ligure). The brakes can then be released and immediately reapplied with another full application Without recharging the brake pipe and auxiliary reservoirs up to 100 pounds pressure. This manner of operating the brakes is taken advantage of upon heavy descending mountain grades. It Will thus be understood that no excess pressure above 50 pounds can reach the brake cylinders from the brake pipe during the above described service operations.

The auxiliary reservoir deplete valve |39 operates the same in'abnormal service or emergency as it does in the described normal '70 pound service or emergency brake pipe and auxiliary reservoir operating pressures. The high pressure emergency application is accomplished in the same usual described manner with a greater brake cylinder pressure gai-ned while operating with the high pressures than when operating with normal pressures.

The release of the brakes is accomplished in the usual describedmanner while operating with abnormal high pressure. The exhaust control valve I 4'I Will automatically reduce the emergency excess pressure from the brake cylinder and bleed the auxiliary reservoir high pressure into the former and its chamber |69, then automatically reduce the excess pressure from the chamber and brake cylinder into the brake pipe when the pressure in the latter is slightly below the pressure in the chamber |69 and the brake cylinder k53 to permit the exhaust control valve device X to reduce the pressure in the usual manner for a ready quick release of the brakes. The auxiliary reservoir deplete valve device will function the same when operating with high abnormal pressure for example, 100 pounds brake pipe and auxiliary reservoir pressures as it does with the normal brake pipe and auxiliary reservoir '70 pounds pressures.

From the above description it is thought that the construction and operation of the invention will be fully understood Without further explanation.

What is claimed is:

1. In an automatic air brake, in combination, a brake pipe, a brake cylinder, an auxiliary reservoir, and a triple valve device operative upon. an

emergency reduction in brake pipe pressure to equalize the auxiliary reservoir With the brake cylinder, and automatic means forthen connecting the brake cylinder to the brake pipe whereby, the equalized pressure is reduced to a predetermined value in a series of steps into the brake pipe 5 to facilitate prompt release.

2. In an automatic air brake, in combination, a quick action chamber, an auxiliary reservoir, a check valve controlled passage leading from the auxiliary reservoir to the quick action chamber, l and means for releasing excess pressure from the auxiliary reservoir to the atmosphere when overcharged.

3. In an automatic air brake, in combination, a brake pipe, a triple valve, an auxiliary reserl voir, a reserve reservoir and a quick action chamber adapted to be charged from the auxiliary reservoir, through a one way check valve, an emergency valve device responsive to brake pipe and quick action chamber pressures, means' in- 2O corporated in said emergency valve device to slowly vent the quick action chamber of abnormal high pressure resulting from an overcharge into the brake cylinder and thereby to the atmosphere when the triple valve is in release position, and

25 means: subject to brake pipe and quick action chamber pressuresI to maintain normal pressure in the quick action chamber after a quick service and service reduction in brake pipe pressure, said means responsive to a further reduction in brake 30 pipe pressure to cause the full service application and reduce said quick action chamber pressure to a predetermined value to establish a following available emergency application.

4. In an automatic air brake, in combination,

35 a brake cylinder, a quick service chamber, constantly coacting with the brake cylinder, means responsive to brake pipe reduction for charging ythe quick service chamber with a definite volume of air under pressure for propagating quick serv- 40 ice application, means for conducting said definite volume into the brake cylinder to minimize brake cylinder leakage, and triple valve means coacting with the second named means for releasing said denite volume from the brake cylinder.

45 5. In an automatic air brake, in combination,

a brake pipe, a brake cylinder, an auxiliary reservoir, adapted to be charged with fluid under pressure from the brake pipe, a deplete valve device, and a triple valve assembly comprising a main 50 slide valve, an auxiliary slide valve superimposed thereupon, a piston subjected on one side to auxiliary reservoir pressure and subjected on the other side to brake pipe pressure, operative upon a light quick service reduction in brake pipe 55 pressure for causing said main valve to connect the auxiliary reservoir with the brake cylinder for a quick service application and simultaneously open a connecting passage from said auxiliary reservoir to a deplete valve chamber, whereupon 60 reservoir pressure is present in said passage and chamber, said deplete valve device in combination with said triple valve assembly, having a control piston, a slide valve, a seat and chamber therefor, said control piston constantly subjected to 65 brake pipe pressure on one side and subjected on the other side to auxiliary reservoir pressure when the triple valve is in application position, a passage controlled by said triple valve and leading from said deplete valve chamber to said triple 70 valve seat and chamber, and so positioned that in application of the said triple valve, reservoir pressure is present in said passage and chamber, a vent passage controlled by said control piston and slide valve leading from said slide valve seat 75 and chamber to the atmosphere and so positioned that the control piston and slide valve on same side are exposed to the atmosphere in said chamber in release position of the triple valve, and yielding means responsive to brake pipe pressure for venting the auxiliary reservoir excess pressure to the atmosphere to prevent overcharged auxiliary reservoirs from causing the triple valves to slowly move into application position while the valves are in` release position upon the train.

6. In an automatic air brake, in combination, a brake pipe, an auxiliary reservoir, a triple valve device responsive to brake` pipe and auxiliary reservoir pressures, a quick action chamber adapted to be charged from the auxiliary reservoir, a brake cylinder, and a quick service chamber constantly coacting with brake cylinder pressure to minimize cylinder leakage, coacting means compensating for brake cylinder leakage and maintaining the brake cylinder pressure direct from the brake pipe into the brake cylinder without the brake cylinder becoming overcharged with excess pressure from the brake pipe, when operating the brakes with normal or abnormal high pressure, and coacting means for quick release of the brakes.

7. In an automatic air brake, in combination, a brake pipe, an auxiliary reservoir, a triple valve through which the auxiliary reservoir is charged, and an auxiliary automatic deplete valve device coacting with the triple valve and brake pipe pressures to vent excess pressure above normal pressure of about seventy pounds auxiliary reservoir pressure to the atmosphere and prevent accidental application of the brakes when in normal release position.

8. In an automatic air brake, in combination, a brake pipe, a brake cylinder, an auxiliary reservoir, and a triple valve device operative upon a reduction in brake pipe pressure to equalize the auxiliary reservoir pressure with the brake cylinder pressure to a predetermined value, and an automatic exhaust control valve coacting therewith, for reducing brake cylinder excess pressure, and bleeding the auxiliary reservoir, such excess pressure release being made into the brake pipe whereby to facilitate prompt brake release.

9. In an automatic air brake, in combination, a brake pipe, a brake cylinder, an auxiliary reservoir, a compensating valve, coacting with brake cylinder pressure, and a triple valve controlling the passage of auxiliary reservoir pressure to the brake cylinder and controlling passage of brake pipe pressure to the compensating valve independent of the auxiliary reservoir, emergency application of the triple valve restricting flow of auxiliary reservoir pressure to the brake cylinder and simultaneously opening the compensating valve, said compensating valve when open permitting passage of brake pipe pressure direct into the brake cylinder whereby brake pipe pressure combines with the retarded flow of auxiliary reservoir pressure into the brake cylinder to effect a light preliminary emergency application, and means coacting with the triple valve to prevent a leaky auxiliary reservoir from releasing the brake, said means coacting with the triple valve and brake pipe pressure to release the brakes.

10. In an automatic air brake, in combination, a triple valve device, a quick action chamber, a brake cylinder, a brake pipe, a piston valve subjected on one' side to quick action chamber pressure and subjected on the other side `to brake pipe pressure, a spring on the last named side of the piston valve coacting with brake pipe pressure to hold said piston on its inward seat and the valve for protecting a leaky auxiliary reservoir valve closed to prevent undesired quick action during service operations, reduction of brake pipe pressure permitting the valve to open and release the quick action chamber pressure, and a piston operated vent valve adapted to be opened by the released quick action chamber pressure when the rst named valve is opened and permit flow cf brake pipe pressure in large volume into the brake cylinder during heavy emergency application, and automatic means coacting with the said triple valve device for reducing brake cylinder excess pressure and bleed the auxiliary reservoir, such excess pressure release being made into the brake pipe whereby to facilitate quick release.

ll. In an automatic air brake, in combination, a triple valve, a chamber, a brake cylinder, an auxiliary reservoir, a brake pipe, a control piston having a valve and chamber therefor, said control piston valve in release position permitting return of pressure from the chamber t0 the brake pipe to permit the said valve to reduce pressure to a predetermined value to move to application position to set the brake, a check valve permitting an increase of brake pipe pressure to flow into the chamber and brake cylinder to compensate for cylinder leakage to apply or release the brake, and a reducing port controlled by the control piston valve for reducing pressure to a predetermined value from the chamber and brake cylin- 30 der into the brake pipe, to coact With the/triple from releasing the brake, and prevent Waste of brake cylinder pressure by repeated reductions and increases of brake pipe pressure before the auxiliary reservoirs are recharged during critical brake operations.

l2. In an automatic air brake, in combination, an emergency valve constantly stabilized, a piston vent valve and constant means for stabilizing said piston independent of the vent valve, stabilizing means to prevent undesired emergency action When operating the brakes with quick service and service applications, and coacting means to release the brakes.

13. In an automatic air brake, in combination, a brake pipe, a brake cylinder, an auxiliary reservoir, a compensating valve coacting with brake pipe pressure, and means in the full service and emergency application position of the brakes for restricting the flow of pressure from the auxiliary reservoir to the brake cylinder and simultaneously opening the compensating valve, thus permitting passage off a larger volume of brake pipe pressure direct into the brake cylinder, providing a greater emergency application, whereupon said compensating valve automatically reduces brake cylinder application excess pressure into the brake pipe to facilitate prompt release.

ALVA L. GOODKNIGHT. 

